The present invention relates to reflectors for collecting and concentrating electromagnetic radiation waves and more particularly to reflectors constructed of film which are deformed into the proper concave shape by placing a pressure differential thereacross. Pressure-shaped film reflectors have been previously developed such as shown in U.S. Pat. No. 3,623,796 and 2,952,189 wherein a film member is stretched across an enclosed space within which a partial vacuum is created to deform the film inwardly providing a curved reflector surface. However, these patents all have a rigid drum or dish-shaped container forming all but the side that the deformable reflective film is on. When used for collecting solar radiation waves for use as an alternate source of energy, large reflective surfaces are necessary such as thirty feet in diameter. The prior structures present structural weight and cost problems when constructed of such a large size and are difficult to fabricate to the required tolerances. There has also been a problem in prior known structures in constructing the reflective film surface to be a truly spherical surface instead of just a concave surface. To construct a truly spherical surface, the film would have to be pre-shaped to a spherical shape and have the same elastic properties about each point in the film.